Interactive Transcript
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We're here with a gorgeous magnified picture
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of the labrum, the acetabulum, and the capsule.
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And let's use our drawing tool to
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help you analyze the individual
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components of labral injuries.
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Let's start out in this area that's
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a slightly different shade of gray.
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And let me pick a color here.
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I think I'll choose blue.
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And this is all hyaline cartilage.
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The hyaline cartilage is going to have a
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transition zone into fibrocartilage.
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And one of the most common types of
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tears is a separation right about here,
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where you see it's a little bit lighter,
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between the labrum and the hyaline area.
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This is an area of disruption that is
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often vertically oriented or inclined.
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Now the labrum may then tilt upward,
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like this, or just completely
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displace, or it may just sit there.
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Depending upon how big and
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how deep this injury is.
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This is one of the most common
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types of acute traumatic labral
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injuries in younger individuals.
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Sometimes when that is very severe, and that
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usually occurs with a twist, with an impaction.
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So, in other words, if you fall on your
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knee with a twist, that'll result
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in this type of tear in a young person.
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You may also flip the labrum up and
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strip away this capsule here, so the
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capsule may also begin to detach from
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the underlying bone and periosteum.
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That is a very serious abnormality that requires
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surgical intervention, usually by arthroscopy.
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Now let me reinitiate my...let me
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get my eraser out here for a moment.
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And let's look at some other
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types of labral injuries.
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I'm gonna draw for you a meniscus in the knee.
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And I'll use the color blue again.
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And I'll try and make it
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a little 3D-ish looking.
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Now when you have a meniscal injury in
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the knee that is vertically oriented,
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it can be vertical in the outer third,
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or it can be vertical and be in the inner
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third, but in a different orientation.
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The one in the inner third
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is known as a radial tear.
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And what that looks like in the knee,
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if you put a triangle right through
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this area, is something like this.
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And then, at the tip,
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it's all what I would call mushy.
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It's filled in with other stuff,
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so it's no longer a meniscus, and the
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meniscus is, as we say, truncated.
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So what happens in the labrum of the hip?
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Well, in the labrum of the hip,
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you can mush the tip of the labrum
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in any one of a number of ways.
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You can have a vertical injury,
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and then it just flips off and detaches.
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You can have a large, macerated,
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horizontal injury, and then the labrum
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eventually rips off and detaches.
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So the concept of radial injuries at the tip of
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the labrum is much more amorphous, even though
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strictly speaking, you'll read in the literature
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something analogous to what we see in the knee.
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That's a hard concept to really
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digest when you're looking at an MR.
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So for simplicity's sake, and I'm using the
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color green now, whenever I see the tip of
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the labrum just truncated off like someone
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came in with a knife and chopped it like some
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celery, I'm going to call that a radial tear.
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So there's a little bit of difference
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between it and the meniscus.
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A little more liberalism, although
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nobody likes to hear a liberal drone
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on for too long, as my son would say.
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And let's look at some other
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kinds of tears real quickly.
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Let's pick another color.
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A very common type of tear that we see
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in adults over a period of time
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is the straight vertical tear.
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Now we've already seen the meniscus
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of the knee, there are two types of
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vertically oriented or up and down tears.
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One radial to the arc of the meniscus,
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and one parallel to the arc of the meniscus.
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The common type of vertical tear
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in the labrum looks like this.
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Straight up and down, and I'd like to use
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a different color, let's go with orange.
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Straight up and down, like this.
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Very common to see these tears in
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people that are 50, 55, 60, 65 that are atraumatic.
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It is very uncommon at the top of
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the hip to have a sulcus there.
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So if you have a vertically oriented
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abnormality, especially if it's 50%
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depth or more, especially if it's not
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smooth and sulcated with a nice round top.
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It's probably, in fact, it's most likely
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a tear of chronic long standing duration.
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And these tears may progressively propagate as
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one gets older and eventually in degenerative
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hips or people with delayed developmental
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dysplasia, it may go through and through and
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now the labrum may detach and lop off and
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add to the symptoms that the patient has from
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other problems like DJD and chondromalacia.
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This is the most common type of tear that
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you're going to see in the adult, elderly
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individual without a specific episode of trauma.
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The last type of tear I'm going to talk about is
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one that parallels the long axis of the labrum.
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It is a little counterintuitive,
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and it runs this way.
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It runs parallel to the long axis of the labrum.
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Now you'll hear people talk about this
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type of tear as a longitudinal tear.
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That's a bit confusing
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because we have a longitudinal tear in the
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meniscus that really doesn't quite match it.
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And it usually occurs right
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in the center of the labrum.
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Now I don't have any objection to using
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the term longitudinal because it's
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running along the long axis of the labrum.
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You'll also hear people refer to these
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as longitudinal horizontal tears.
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You'll hear them referred
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to as horizontal tears.
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And frankly, I don't care which one you use,
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as long as you convey that the tear is running
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along the center of the long axis of the labrum
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and frequently these tears will then bend like
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Beckham and go right into the hyaline cartilage
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and you'll see a line into the hyaline space so
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that there is a hyaline to labral transition.
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And these are often very symptomatic tears.
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More on the types of labral tears
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and their implication in the next
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small vignette in this series.
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